feat: public text items, wall, and detail API

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/main.py

@@ -2,6 +2,7 @@ from contextlib import asynccontextmanager
 
 from fastapi import FastAPI
 
+from app.api.public import router as public_router
 from app.config import settings
 from app.db import Base, engine
 from app import models  # noqa: F401 — register models with Base.metadata
@@ -16,6 +17,7 @@ async def lifespan(_app: FastAPI):
 
 
 app = FastAPI(title="MincedPad", lifespan=lifespan)
+app.include_router(public_router)
 
 
 @app.get("/api/health")